Year	% of total
1971	2.1912350597609564
1972	1.4044410704118429
1973	1.0861948142957254
1974	1.478650938694135
1975	0.9562841530054645
1976	0.7366226546212649
1977	0.9474367293964957
1978	0.9783121169259784
1979	1.1061476281642204
1980	0.9710681749924918
1981	0.5673758865248227
1982	0.3883670520231214
1983	0.5453601108033241
1984	0.5695224147750386
1985	0.4426592343634724
1986	0.4477838494231937
1987	0.3236960200102994
1988	0.5019942236281116
1989	0.5380930507251132
1990	0.6056975505857295
1991	0.7926322941043255
1992	0.702028081123245
1993	0.7453190329031085
1994	0.40952778938570833
1995	0.5939481499317762
1996	0.7177394983378664
1997	0.9189876997030962
1998	0.6856092733955329
1999	0.7107369583218327
2000	0.5920702501330495
2001	0.49022811948493367
2002	0.6752022421810306
2003	0.8096141682479444
2004	0.562875783548676
2005	0.44322774084213273
2006	0.5707693241848321
2007	0.6865637766681798
2008	0.7805871372815205
2009	0.8514717491823617
2010	0.5575673966775881
2011	0.5574324324324325
2012	0.602344258736705
2013	0.6635318704284221
2014	0.5370236496953423
2015	0.23659305993690852